Search

[Display omitted] • The insertion of pillar ligands of UPC-190 series MOFs can lead to changes in the interpenetrating structure. The degree of interpenetration can be managed by introducing different pillars. • Theoretical calculations demonstrate that the fluorine atom on pillar ligands is an effective interaction site for C 2 H 2 molecules. This means that fluorine atoms can act as active sites that interact with C 2 H 2 molecules, thereby influencing their adsorption behavior. • The formation of interpenetrating structures and the stepwise fluorination strategy gradually improve the IAST selectivity and C 2 H 2 uptake of the sample. This strategy proves guidance for designing MOFs for challenging gas separations. The efficient separation of C 2 H 2 /CO 2 possesses great commercial and research value and remains challenging due to their similar molecular sizes and physical properties. Functionalization is a powerful strategy for precisely regulating the pore environment of porous adsorbents, notably metal–organic frameworks (MOFs), for recognizing target molecules. Here, we construct three interpenetrated MOFs using a stepwise fluorinated pillar-ligand strategy. Interestingly, the degree of interpenetration can be managed by introducing different pillars. The unique interpenetrating structure cooperates with fluorine-rich pore environment significantly improves the C 2 H 2 uptake and the C 2 H 2 /CO 2 separation selectivity. The optimized difluorine-functionalized UPC-193 exhibits the highest C 2 H 2 adsorption capacity (80.45 cm3/g) and separation efficiency (C 2 H 2 /CO 2 uptake ratio of 1.9) among UPC-190 systems at ambient conditions. Ideal adsorbed solution theory (IAST) calculations, molecular modeling studies, and breakthrough experiments comprehensively demonstrate that UPC-193 is an effective MOF adsorbent for equimolar C 2 H 2 /CO 2 separation. The stepwise pillar-ligand fluorination strategy proves to be an effective approach to extend the functionality of MOFs for challenging gas separations. [ABSTRACT FROM AUTHOR]

The separation of ethylene (C2H4) from a mixture of ethane (C2H6), ethylene (C2H4), and acetylene (C2H2) at normal temperature and pressure is a significant challenge. The sieving effect of pores is powerless due to the similar molecular size and kinetic diameter of these molecules. We report a new modification method based on a stable ftw topological Zr‐MOF platform (MOF‐525). Introduction of a cyclopentadiene cobalt functional group led to new ftw‐type MOFs materials (UPC‐612 and UPC‐613), which increase the host‐guest interaction and achieve efficient ethylene purification from the mixture of hydrocarbon gases. The high performance of UPC‐612 and UPC‐613 for C2H2/C2H4/C2H6 separation has been verified by gas sorption isotherms, density functional theory (DFT), and experimentally determined breakthrough curves. This work provides a one‐step separation of the ternary gas mixture and can further serve as a blueprint for the design and construction of function‐oriented porous structures for such applications. [ABSTRACT FROM AUTHOR]

In practical industrial applications, the separation of light hydrocarbon mixtures is a very important technology. In recent years, some progress has been made in metal‐organic framework materials for light hydrocarbon separation, but further research is still needed. This Minireivew presents a systematic discussion on the latest developments and separation mechanisms of metal‐organic framework materials for C2 and C3 mixtures, discusses the problems faced by metal‐organic framework materials in the study of light hydrocarbon adsorption and separation, and provides a reference for the design, preparation and process development of low‐carbon hydrocarbon adsorption and separation materials in the future. [ABSTRACT FROM AUTHOR]

Solid‐state transformations in metal–organic frameworks (MOFs) are important and have led to the creation of new MOF structures. Solid‐state transformations from interpenetrated to non‐interpenetrated networks involving rearrangement of secondary building units (SBUs) in a single‐crystal‐to‐single‐crystal (SCSC) fashion have not been explored to date. Herein, we report the sequential, thermally stimulated solid‐state transformations in a barium‐organic framework (UPC‐600). The two‐fold interpenetrated framework of UPC‐600 is converted at 373 K into UPC‐601, a non‐interpenetrated framework. This proceeds in a SCSC fashion and involves the rearrangement of two proximate rod‐shaped SBUs in different nets to generate a new rod‐shaped SBU. At 473 K, a continuous solid‐state transformation involving a second rearrangement occurred, UPC‐601 converted into UPC‐602 by the rearrangement of the 1D rod‐shaped SBU to a 2D layer SBU. This is the first example of such a thermally driven stepwise transformation involving simultaneous cleavage and regeneration of multiple bonds. [ABSTRACT FROM AUTHOR]

Two series of lanthanide-based metal–organic frameworks, namely {[Ln(BIPA-TC)0.5(DMA)2(NO3)]·DMA·H2O}n (1-Ln, Ln = Eu, Dy, Sm, Nd) and {[Ln2(BIPA-TC)1.5(DMA)3(H2O)2]·2DMA·2H2O}n (2-Ln, Ln = Eu, Dy, Sm, Nd), were successfully constructed via a solvent regulation strategy based on a π-electron rich tetra-carboxylate ligand (H4BIPA-TC). 1-Ln shows a 4-connected lvt topology with the point symbol of {42·84}, but 2-Ln displays a new 4,4,6-connected wxk1 topology with the point symbol of {43·83}4{46·66·83}2{86}. The solid-state luminescence property and the microporous nature of Eu-MOFs (1-Eu and 2-Eu) indicate that they can potentially be used as luminescent sensors. Fluorescence measurements indicate that Fe3+ exhibits the quenching effect for 1-Eu with the quenching efficiency of 93.1%. 2-Eu is the first MOF sensor for Mg2+ with the lowest detection limit of 1.53 × 10−10 mol L−1 and displays good recyclable capability. Simultaneously, in the presence of other metal ions (Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pd2+, Al3+, Cr3+and Fe3+), 2-Eu can maintain the selective sensing of Mg2+, indicating its potential for Mg2+ turn-on sensing. [ABSTRACT FROM AUTHOR]

Linker desymmetrization has been witnessed as a powerful design strategy for the discovery of highly connected metal–organic frameworks (MOFs) with unprecedented topologies. Herein, we introduce molecular pivot‐hinge installation as a linker desymmetrization strategy to evolve the topology of highly connected rare‐earth (RE) MOFs, where a pivot group is placed in the center of a linker similar to a hinge. By tuning the composition of pivot groups and steric hindrances of the substituents on various linker rotamers, MOFs with various topologies can be obtained. The combination of L‐SO2 with C2v symmetry and 12‐connected RE9 clusters leads to the formation of a fascinating (4,12)‐c dfs new topology. Interestingly, when replacing L‐SO2 with a tetrahedra linker L‐O, the stacking behaviors of RE‐organic layers switch from an eclipsed mode to a staggered stacking mode, leading to the discovery of an intriguing hjz topology. Additionally, the combination of the RE cluster and a linker [(L‐(CH3)6)] with more bulky groups gives rise to a flu topology with a new 8‐c inorganic cluster. The diversity of these RE‐MOFs was further enhanced through post‐synthetic installation of linkers with various functional groups. Functionalization of each linker with acidic and basic units in the mesoporous RE‐based PCN‐905‐SO2 allows for efficient cascade catalytic transformation within the functionalized channels. [ABSTRACT FROM AUTHOR]

Highly selective detection of trace metal ions has become one of the most urgent issues in public security and living systems. Developing a highly efficient fluorescent sensor for manganese(ii) (Mn2+) ions is a huge challenge. Herein, by utilizing the solvent regulation approach, a pair of terbium metal–organic frameworks (UPC-36, [Tb2(btdc)3(DMF)(H2O)4]·DMF and UPC-37, [Tb2(btdc)3(H2O)6]) based on a π-electron-rich ligand (H2btdc = 2,2′-bithiophene-5,5′-dicarboxylic acid) has been chosen as highly efficient sensors for the selective detection of Mn2+ ions. Interestingly, the fluorescence of UPC-36 can be quenched by Mn2+, Cu2+, Al3+, Cr3+ and Fe3+ ions, while UPC-37 can only be quenched by Mn2+ ions. For detecting Mn2+ ions, the limit of detection (LOD) values are calculated to be 0.813 mM and 0.715 mM for UPC-36 and UPC-37 respectively. According to the ICP results, UPC-37 has stronger interactions with Mn2+ ions because of the more regular arrangement of ligands existing in UPC-37, so it exhibits a high sensitivity and selectivity (Ksv = 5.25 × 105 M−1). [ABSTRACT FROM AUTHOR]

Effective strategies in metal–organic frameworks for C 2 H 2 /CO 2 separation from the perspective of C 2 H 2 -preference and CO 2 -preference. [Display omitted] • Summarize recent advances in MOFs for C 2 H 2 /CO 2 separation from the perspective of C 2 H 2 -preference and CO 2 -preference. • Discuss several well-developed strategies for C 2 H 2 /CO 2 separation as follows: (1) Functional site regulation: metal site regulation, ligand functional modification, and inorganic anion introduction; (2) Structural regulation: pore segmentation and reticular chemistry; (3) Acetylene nanotrap; (4) Unconventional adsorption. • Summarize the potential obstacles and future development prospects from academia to final industrial implementation. The high-efficiency separation of C 2 H 2 /CO 2 has important research significance and industrial value. The currently reported metal–organic framework (MOF) adsorbents for the separation of C 2 H 2 /CO 2 are generally based on unsaturated metal sites, strong hydrogen bonds or strong electrostatic interaction sites, which suffer from difficulties in combining selectivity and capacity. Significant efforts have been devoted to solving this trade-off effect, and considerable achievements have been made. Herein, we review the research progress of MOFs for C 2 H 2 /CO 2 separation in the past few years according to the properties of the material structure, and prospect the future research directions. [ABSTRACT FROM AUTHOR]

Nature gas plays an important part in daily life and petrochemical industry, but it always coexists with impurities of considerable amount, which hinders full utilization of methane and thus makes its purification an urgent issue to be addressed. Herein, via solvothermal reaction of N,N′-bis(3-methylbenzoic acid-4-yl)-1,4,5,8-naphthalenetetracarboxydiimide (H 2 L) and cadmium cation, we obtained a layer structure of [Cd 2 (L) 2 (H 2 O) 2 ]·4H 2 O (UPC-71) with sql/Shubnikov tetragonal plane net topology, where tiny pores are formed due to direct dense packing of layer by layer. After adding 1, 2-bis(4-pyridyl) ethane (BPEA) as ancillary ligand, a rare 8-fold interpenetrated framework, [Cd(L)(BPEA)]·4H 2 O (UPC-72), was obtained. Limited by their tiny pore volume, UPC-71 and UPC-72 both display somewhat small gas sorption capacities, but an obvious increase in the adsorption/separation performance can be observed in UPC-72 due to the effect of pore confinement strategy. In particular, the quantities of C 2 H 2 and CO 2 adsorbed are 1.54 and 0.83 ​mmol/g at ambient condition, and the IAST selectivities of C 2 H 2 /CH 4 and CO 2 /CH 4 are up to 20.1 and 4.7 for UPC-72. With the aid of GCMC simulation, we prove that there exist stronger binding interactions between C 2 H 2 and CO 2 with the active sites in UPC-72 , and thus enhances the separation selectivity. [Display omitted] • Two Cd-MOF (UPC-71 and UPC-72) were designed and synthesized. • Rare 8-fold interpenetrated structure is obtained via pore confinement strategy. • A new strategy is explored to improve adsorption/separation performance. • The IAST selectivities of UPC-72 exhibit a great improvement compared with UPC-71. • Interspersed behavior improved the sorption capacity effectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • New 3D bulk MOF and 2D ultrathin MOF nanosheets are synthesized. • The planar micro-supercapacitors with the interdigital microelectrodes are achieved based on MOF bulk and MOF nanosheets. • The MOF-nanosheets for micro-supercapacitors displays enhanced performance than MOF bulk. Due to the advantages of ultrahigh power density, long lifespan and easy integration with wearable and microscale electronics, micro-supercapacitors (MSCs) have attracted great interest in recent years. However, new high-performance electrode materials for such micro-electrochemical energy storage devices require deep excavation. Herein, we precisely synthesized a new 3D bulk MOF and new 2D ultrathin MOF nanosheets with a thickness of less than 10 nm, and utilized them as high-capacitance microelectrode materials for sophisticated all-solid-state MSC devices respectively. Notably, the MSCs based on MOF nanosheets displayed a high areal capacitance of 28.3 mF·cm−2, and a volumetric capacitance of 15.7 F·cm−3 at 0.2 mA·cm−2. Especially, our MSCs exhibited remarkable energy density of 8.7 mWh·cm−3 at a power density of 110.3 mW·cm−3, and excellent cycling lifespans with retention of 96.0% after 10,000 cycles, and all performances are better than the MSCs based on MOF bulks. This work provides a new way to further explore the inherent advantages of MOFs and stimulates the synthesis of advanced MOFs materials for application in microscale energy storage. [ABSTRACT FROM AUTHOR]

Cobalt, ethylene purification, metal-organic frameworks (MOFs), one-step purification, ternary gas mixture Keywords: cobalt; ethylene purification; metal-organic frameworks (MOFs); one-step purification; ternary gas mixture EN cobalt ethylene purification metal-organic frameworks (MOFs) one-step purification ternary gas mixture 11636 11636 1 05/06/21 20210510 NES 210510 B Eine CpCo-Einheit b wurde in einen kubischen Käfig eingeführt, um eine sphärische Kraftfläche zu erzeugen, wodurch der kubische Käfig in zwei Teile geteilt wird. Rücktitelbild: One-step Ethylene Purification from an Acetylene/Ethylene/Ethane Ternary Mixture by Cyclopentadiene Cobalt-Functionalized Metal-Organic Frameworks (Angew. [Extracted from the article]

Keywords: cobalt; ethylene purification; metal-organic frameworks (MOFs); one-step purification; ternary gas mixture EN cobalt ethylene purification metal-organic frameworks (MOFs) one-step purification ternary gas mixture 11532 11532 1 05/06/21 20210510 NES 210510 B A CpCo group b was introduced in a cubic cage to generate a sphere-like force surface, thus dividing the cubic cage into two parts. Back Cover: One-step Ethylene Purification from an Acetylene/Ethylene/Ethane Ternary Mixture by Cyclopentadiene Cobalt-Functionalized Metal-Organic Frameworks (Angew. Based on the high selectivity of the CpCo group, high-purity ethylene is obtained from an acetylene/ethylene/ethane ternary mixture, as reported by Daofeng Sun et al. in their Research Article on page 11350. [Extracted from the article]

The discovery of metal–organic frameworks (MOFs) mimicking inorganic minerals with intricate topologies requires elaborate linker design guidelines. Herein, the concept of linker desymmetrization into the design of tetratopic linker based Zr‐MOFs is applied. A series of bent tetratopic linkers with various substituents are utilized to construct Zr‐MOFs with distinct cluster connectivities and topologies. For example, the assembly between a bent linker L‐SO2 with C2v symmetry and an 8‐connected Zr6 cluster leads to the formation of an scu topology, while another flu topology can be obtained by the combination of a novel 8‐connected Zr6 cluster and a bent linker L‐O with C1 symmetry. Further utilization of restricted bent linker [(L‐(CH3)6)] gives rise to a fascinating (4, 6)‐c cor net, originated from the corundum lattice, with an unprecedented 6‐c Zr6 cluster. In addition, the removal of toxic selenite ions in aqueous solution is performed by PCN‐903‐(CH3)6 which exhibits rapid and efficient detoxification. This work uncovers new structural opportunities for Zr‐MOFs via linker desymmetrization and provides novel design strategies for the discovery of sophisticated topologies for practical applications. [ABSTRACT FROM AUTHOR]

Al-MOFs have diverse chemical structures and tunable properties for potential applications in adsorption, separation, catalysis, proton conduction, chirality, and superhydrophobicity fields. [Display omitted] • Systematically summarized the similarities between secondary building units and linkers from the structural aspect of Al-MOFs, the structurally-led approach is distinctive and helps to better understand the crystal chemistry of Al-MOFs. • Introduced the research progress and highlighted several exciting discoveries of studying Al-MOFs. • Demonstrated the development trends, emerging challenges, and opportunities primarily oriented to their scalable production, and aimed at exploring the future application prospects of Al-MOFs from academic research to industrial production. It is essential to explore metal–organic frameworks (MOFs) with high durabilities and versatile properties for practical applications. Multiple metal ions have been utilized to construct MOFs, among which the aluminum ion (Al3+) has drawn intensive attention due to its low toxicity, abundant reserves in the earth, low cost, and sustainability. As an attractive MOF family in virtue of its diverse structures and functions, Al-MOFs exhibit high physicochemical stability and have wide applications in many scientific and engineering fields, due to the diverse secondary building units (SBUs) of Al3+ and the strong Al-O bond. In this review, we systematically summarize the SBUs and linkers from a structural perspective. We also highlight the research progress of Al-MOFs with novel topologies and structures. According to the composition of Al-metal nodes, Al-MOFs can be divided into Al3+-ions, Al3+-chains, or Al3+-clusters. In addition, the potential applications of Al-MOFs in various fields, including adsorption, separation, photocatalysis, electrochemistry, chirality, and superhydrophobicity are discussed. From the perspective of Al-MOF structures, the relationship between the structure and performances of Al-MOFs is reviewed, and the future application prospects of Al-MOFs are discussed. [ABSTRACT FROM AUTHOR]